One of the best things about building websites with Drupal is that there are thousands of modules that help you quickly create functionality.

To set things up, you need to download Drush and add it to your path. For example, you might unpack it into /opt/drush and then add the following line to your ~/.bashrc:

PATH=/opt/drush:$PATH
export PATH

Reload your ~/.bashrc with source ~/.bashrc, and the drush command should become available. If you're on Microsoft Windows, it might need some more finagling. (Or you can just give up and use a virtual image of Linux to develop your Drupal websites. You'll probably end up much happier. ;) )

Once you've installed Drush, what can you do with it?

Drush is a huge time-saver. For example, I install dozens of modules in the course of building a Drupal website. Instead of copying the download link, changing to my sites/all/modules directory, pasting the download URL into my terminal window after wget, unpacking the file, deleting the archive, and then clicking through the various module enablement screens, I can just issue the following commands to download and enable the module.

drush dl modulename
drush en -y modulename

(The -y option means say yes to all the prompts.)

So much faster and easier. You can use these commands with several modules (module1 module2 module3), and you can use drush cli to start a shell that's optimized for Drush.

Drush is also useful if you've screwed up your Drupal installation and you need to disable themes or modules before things can work again. In the past, I'd go into the {system} table and carefully set the status of the offending row to 0. Now, that's just a drush dis modulename.

Drush has a bucketload of other useful commands, and drush help is well worth browsing. Give it a try!